[Study of the morphology of heel spur and clinical significance: base on three-dimensional computed tomography]

OBJECTIVES

To evaluate the characteristic morphology of heel spur, and to investigate the relationship of heel spur and plantar heel pain.

METHODS

From June 2005 to April 2009, 210 cases (254 feet) with heel spur (according to Denis Pain Scale) were divided into cases group 1 (P2, n = 46), 2 (P3, n = 44), 3 (P4, n = 42), 4 (P5, n = 36) and controls group (P1, n = 42). Three-dimensional reconstruction of heel spur was performed in all groups using volume rendering based on multi-slice CT data by Super Image orthopedics edition 1.0. The characteristic morphology of heel spur was observed and the data were measured and analyzed, involving the width of basilar part, the length, the angle between heel spur and planta pedis, and the angle between the longitudinal axis of calcaneus and heel spur.

RESULTS

Parts of cases groups displayed coarse arcuate edge and undersurface with one or more little heel spurs adhere to heel spur, of which the numbers were greater than controls group, especially in cases group 4. No significant difference of the width of basilar part of heel spur was found among 5 groups (F = 2.32, P > 0.05). However, obvious difference was found in the length, the angle between heel spur and planta pedis, and the angle between the longitudinal axis of calcaneus and heel spur (F = 8.23, 6.82, 5.87, P < 0.05). Compared with the controls group, the angle between heel spur and planta pedis of cases groups had higher degrees, but the difference of the other data presented irregular.

CONCLUSIONS

The characteristic morphology of heel spur varies in patients associated with plantar heel pain. No correlation is found between the severity and the morphological data, including the width of basilar part, the length, the angle between heel spur and planta pedis, and the angle between the longitudinal axis of calcaneus and heel spur.

Influence of lifestyle factors on quantitative heel ultrasound measurements in middle-aged and elderly men

We examined the distribution of quantitative heel ultrasound (QUS) parameters in population samples of European men and looked at the influence of lifestyle factors on the occurrence of these parameters. Men aged between 40 and 79 years were recruited from eight European centers and invited to attend for an interviewer-assisted questionnaire, assessment of physical performance, and quantitative ultrasound (QUS) of the calcaneus (Hologic; Sahara). The relationships between QUS parameters and lifestyle variables were assessed using linear regression with adjustments for age, center, and weight. Three thousand two hundred fifty-eight men, mean age 60.0 years, were included in the analysis. A higher PASE score (upper vs. lower tertile) was associated with a higher BUA (beta coefficient = 2.44 dB/ Mhz), SOS (beta = 6.83 m/s), and QUI (beta = 3.87). Compared to those who were inactive, those who walked or cycled more than an hour per day had a higher BUA (beta = 3.71 dB/Mhz), SOS (beta = 6.97 m/s), and QUI (beta = 4.50). A longer time to walk 50 ft was linked with a lower BUA (beta = -0.62 dB/ Mhz), SOS (beta = -1.06 m/s), and QUI (beta = -0.69). Smoking was associated with a reduction in BUA, SOS, and QUI. There was a U-shaped association with frequency of alcohol consumption. Modification of lifestyle, including increasing physical activity and stopping smoking, may help optimize bone strength and reduce the risk of fracture in middle-aged and elderly European men.

The effect of including quantitative heel ultrasound in models for estimation of 10-year absolute risk of fracture

The role of quantitative ultrasound (QUS) in clinical practice is debatable. An unanswered question is that whether combining QUS and BMD measurements could improve the prediction of fracture risk. We examined this in a sample of men and women in the European Prospective Investigation into Cancer (EPIC)-Norfolk who had both heel QUS and hip DXA between 1995 and 1997 and were followed for any incident fracture up to 2007. From 1455 participants (703 men) aged 65-76 years at baseline, 79 developed a fracture over 10.3+/-1.4 years of follow-up. Two separate sex-stratified Cox proportional-hazard models were used including clinical risk factors and total hip BMD. Heel broadband ultrasound attenuation (BUA) was also included in the second model. Global measures of model fit, area under ROC curve, and the Hosmer-Lemeshow statistic showed relative superiority of the model including BUA. Using each model, we calculated 10-year absolute risk of fracture for all participants and categorized them in groups of < 5%, 5% to < 15%, and > or = 15%. Comparison of groupings showed a total re-classification of 16.6% of participants after inclusion of BUA with the greatest re-classification (30.7%) among the group with intermediate risk. Adding a QUS measurement to models based on clinical risk factors and BMD improves the predictive power of models and suggests that further attention should be paid to QUS as a clinical tool for fracture risk assessment.

Assessment of trabecular bone structure of the calcaneus using multi-detector CT: correlation with microCT and biomechanical testing

The prediction of bone strength can be improved when determining bone mineral density (BMD) in combination with measures of trabecular microarchitecture. The goal of this study was to assess parameters of trabecular bone structure and texture of the calcaneus by clinical multi-detector row computed tomography (MDCT) in an experimental in situ setup and to correlate these parameters with microCT (microCT) and biomechanical testing. Thirty calcanei in 15 intact cadavers were scanned using three different protocols on a 64-slice MDCT scanner with an in-plane pixel size of 208 microm and 500 microm slice thickness. Bone cores were harvested from each specimen and microCT images with a voxel size of 16 microm were obtained. After image coregistration, trabecular bone structure and texture were evaluated in identical regions on the MDCT images. After data acquisition, uniaxial compression testing was performed. Significant correlations between MDCT- and microCT-derived measures of bone volume fraction (BV/TV), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) were found (range, R(2)=0.19-0.65, p<0.01 or 0.05). The MDCT-derived parameters of volumetric BMD, app. BV/TV, app. Tb.Th and app. Tb.Sp were capable of predicting 60%, 63%, 53% and 25% of the variation in bone strength (p<0.01). When combining those measures with one additional texture index (either GLCM, TOGLCM or MF.euler), prediction of mechanical competence was significantly improved to 86%, 85%, 71% and 63% (p<0.01). In conclusion, this study showed the feasibility of trabecular microarchitecture assessment using MDCT in an experimental setup simulating the clinical situation. Multivariate models of BMD or structural parameters combined with texture indices improved prediction of bone strength significantly and might provide more reliable estimates of fracture risk in patients.

[Diagnostics of the retrocalcaneal bursitis: possibilities of the use of new anatomical data]

The anatomy and histology of the normal retrocalcaneal bursa (RB) was studied on both embalmed and fresh cadaverous material. The bursa is a constant structure, its upper and posterior walls are completely covered with the unilayered synovial membrane. Its anterior wall represents the superior facet of the calcaneal tuberosity, the posterior one corresponds to the anterior surface of the insertional part of the Achilles tendon. The superior wall is formed by the adipose tissue of the inferior part of Kager's triangle, extending into the cavity of the bursa in a form of constant large and irregularly shaped synovial fold. The normal anatomical features as well as some pathological changes of the bursa and its neighbourhood were demonstrated on examples of some case reports, by use of the ultrasonography and magnetic resonance investigations. In healthy individuals the space of the bursa was not figured in the ultrasonographic investigations, but was well apparent in the MR images. The pathological changes of the bursa are detectable by using of both methods, but the MR images present substantially precise quality of depiction. The authors recommend the use of presented new anatomical data for the improvement in differential diagnostic of the wide spectrum of achillar enthesopathies.

Accessory anterolateral talar facet as an etiology of painful talocalcaneal impingement in the rigid flatfoot: a new diagnosis

A retrospective review identified six patients with seven painful rigid flatfeet. In each case, pain was localized laterally to an accessory facet of the anterolateral talus. cross-sectional imaging demonstrated no evidence of tarsal coalition. In five of the six, preoperative magnetic resonance imaging (MRI) was obtained and in each case demonstrated focal abutting bone marrow edema consistent with impingement between the accessory facet and the anterior calcaneus.Seven feet in six patients underwent resection of the accessory facet with additional subtalar joint-sparing reconstructive procedures. At an average follow-up of 11 months, clinical results were graded as four good and two fair.An association between this accessory facet and pain in the rigid flatfoot has not been previously reported. Obesity was universal and may represent a risk factor for facet impingement. At early follow-up, facet resection with subtalar joint-sparing flatfoot reconstruction provided good results with symptomatic and functional improvement in the majority of patients.

Successful treatment of bilateral calcaneal intraosseous lipomas using endoscopically assisted tumor resection

BACKGROUND

Intraosseous lipoma is a rare benign bone tumor. Removal is required when there is pain or the lesion is large enough to lead to a pathological fracture. However, conventional surgery requires non-weight-bearing for at least 6 weeks. Here, we present a case with bilateral calcaneal intraosseous lipomas successfully treated by the use of endoscopically assisted curettage.

CASE PRESENTATION

A 30-year-old female noted pain in both heels for 1 year. Radiological findings revealed well-defined lytic lesions at the neck of both calcanei. Magnetic resonance (MR) images showed hyper-intense signals on the T1 and T2 sequences. Curettage was performed through small bone fenestrations in the medial and lateral aspects under observation with a 2.7-mm-diameter Hopkins telescope. The bone void was filled with beta-tricalcium phosphate (beta-TCP). Full weight-bearing was permitted the day after the surgery.

CONCLUSION

Endoscopically assisted curettage is feasible in patients with benign bone tumors of the calcanei to avoid a long period of non-weightbearing post-operatively.

OST risk index and calcaneus bone densitometry in osteoporosis diagnosis

The gold-standard method for osteoporosis diagnosis is by dual-energy X-ray absorptiometry (DXA) of the lumbar spine and/or hip. DXA is expensive and alternative approaches are being analyzed. The objective of this study was to evaluate whether the Osteoporosis Self-Assessment Tool (OST) combined with calcaneal DXA improves the sensitivity and specificity of the DXA. One hundred and sixty-one (67 males and 94 females) outpatients referred due to suspected osteoporosis or lumbar pain were included. Hip, spinal, or calcaneal DXA was performed in all patients and the OST index was administered. The cutoff point for patients of high- or low-risk osteoporosis was 2 for women and 3 for men. The mean OST index value was 3.62+/-4.3. Twenty-seven percent of the patients were osteoporotic. Sixty-two percent presented a low risk and 38% a high risk. In men, the OST had a sensitivity of 39% and a specificity of 86%, whereas in women the sensitivity was 94% with a specificity of 59%. The combination of the calcaneal DXA with the OST index did not modify the validity of DXA in men. In women, the sensitivity of the different cutoff points was improved at the expense of a decrease in the specificity without modifying the area under the curve. The combination of the calcaneal DXA with the OST index did not improve the value of each of the separate techniques. The OST index is useful in women to facilitate the densitometry indication for hip and/or spine.

Clinical significance of musculoskeletal finite element model of the second and the fifth foot ray with metatarsal cavities and calcaneal sinus

AIM

The aim of this study was to establish musculoskeletal finite element (FE) model of the second and the fifth foot ray accounting for metatarsal cavities and calcaneal sinus. The model was then used to predict the effects of metatarsal cavities and calcaneal sinus on internal stresses/strains of plantar longitudinal arches.

MATERIALS AND METHODS

The geometry of foot bones and soft tissues were constructed by CT and MRI images of Virtual Chinese Human "female No. 1". Two types of nonlinear FE models of sagittal foot rays were developed with or without metatarsal cavities and calcaneal sinus using ANSYS software package. The sagittal trabecular architecture of metatarsals and calcaneus were obtained by cutting, defatting and bleaching fresh foot specimen of a cadaver.

RESULTS

The model proposed was able to describe the isostatic stress flows in sagittal planes of plantar longitudinal arches. The size of metatarsal cavity or calcaneal sinus could affect stress/strain distributions on metatarsals and calcaneus, but had almost no effects on stress/strain of other foot bones and plantar soft tissues. During balance standing, the maximum von Mises stresses were predicted at the shaft and the basis of metatarsals, while the maximum strains of bony regions were found around metatarsal cavities. Among plantar soft tissues, relative high tensions were burdened by plantar fascia, followed by long plantar ligament. The minimum tensions occurred in plantar intrinsic muscles.

CONCLUSIONS

The study shows that the tension/compression stress flows are geometrically similar with the tension/compression trabecular architectures in sagittal sections of metatarsal and calcaneus. The FE predictions of stress/strain concentration on metatarsals and fascia are useful in enhancing biomechanical knowledge on metatarsal stress fractures and plantar fasciitis.

Posterosuperior osteochondritis of the calcaneus

Osteochondritis of the posterosuperior area of the talocalcaneal surface is a relatively uncommon injury, and only 1 case has been described in the literature. We present a 37-year-old man who complained of pain in the tarsal canal area during walking and when standing up. The magnetic resonance imaging study showed an osteochondral signal in the posterosuperior medial area of the calcaneus on the talocalcaneal surface. The persistence of pain and lack of improvement with conservative treatment made arthroscopic debridement of the injury necessary. The arthroscopic procedure was performed through 2 medial portals, made under fluoroscopy, marked with needles, and dissected with mosquito clamps, and the affected surface could be fully visualized, showing a chondral lesion. Debridement of the osteonecrotic area was performed, and the Steadman technique was used on the injured bone surface. The patient was pain-free, and limited activity (i.e., standing up and walking without symptoms) was allowed. After 24 months, the patient remains asymptomatic with weight-bearing working activities and when standing. Arthroscopic curettage and scission of the injury have been shown to yield good or excellent outcomes in 75% to 80% of patients with regard to the talar surface.

Recurrent hypertrophic peroneal tubercle associated with peroneus brevis tendon tear

Stenosing peroneal tenosynovitis resulting from hypertrophy of the peroneal tubercle has been well described. Successful surgical treatment addresses the hypertrophied peroneal tubercle as well as any intrinsic tendon pathology. We report a case of recurrent foot pain caused by stenosing peroneal tenosynovitis in a 16-year-old woman. Four months after excision of a hypertrophic peroneal tubercle, the patient developed a recurrence of symptoms. Imaging studies, repeat operative exploration, and pathologic specimen demonstrated a recurrence of the peroneal tubercle hypertrophy associated with a longitudinal tear of the peroneus brevis tendon. Re-resection of the hypertrophied tubercle and peroneal tendon repair resulted in a resolution of symptoms.

Pseudo-cysts, lipomas, infarcts and simple cysts of the calcaneus: are there different or related lesions?

Pseudocysts, lipomas, infarcts and simple cysts of the calcaneus are described as different entities in the medical literature. However, some evolutions or associations may suggest a relationship which is not yet demonstrated in all cases. The aim of this article is to describe each lesion and emphasize their different characteristics that may suggest a relationship between them.

Endoscopic calcaneoplasty (ECP) as a surgical treatment of Haglund's syndrome

Posterior calcaneal exostosis treatment modalities showed many controversial opinions. After failure of the conservative treatment, surgical bursectomy and resection of the calcaneal exostosis are indicated by many authors. But clinical studies also show a high rate of unsatisfactory results with a relative high incidence of complications. The minimal surgical invasive technique by an endoscopic calcaneoplasty (ECP) could be an option to overcome some of these problems. We operated on 81 patients with an age range between 25 and 55 years, 40 males and 41 females. The radiologic examination prior to surgery documented in all cases a posterior superior calcaneal exostosis that showed friction to the Achilles tendon. All patients included in the study had neither clinical varus of the hind foot nor cavus deformities. All patients had undergone a trial of conservative treatment for at least 6 months and did not show a positive response. The average follow-up was 35.3 months (12-72). According to the Ogilvie-Harris-Score, 34 patients presented good and 41 patients excellent results, while three patients showed fair results, and three patients only poor results. All the post-operative radiographs showed sufficient resection of the calcaneal spur. Only minor postoperative complications were observed. ECP is an effective and of minimal-invasive procedure for the treatment of patients with calcaneal exostosis. After a short learning curve, the endoscopic exposure is superior to the open technique has less morbidity, less operating time, and nearly no complications; moreover, the pathology can better be differentiated.

Anterior process calcaneal fractures: a systematic evaluation of associated conditions

OBJECTIVE

The objective was to evaluate the association, by MRI, of anterior calcaneal process fractures with tarsal coalitions, ankle sprains, and bifurcate ligament abnormalities.

DESIGN AND PATIENTS

A retrospective review of 1,479 foot and ankle MR images was performed, over a period of 5 years, for isolated anterior process fractures of the calcaneus. Fifteen 1.5-T MR examinations were systematically evaluated by two radiologists in consensus. Marrow edema patterns, presence of a calcaneonavicular coalition, as well as bifurcate and anterior talofibular ligaments, were evaluated.

RESULTS

There were 15 fractures of the anterior calcaneal process with an incidence of 1%. The average patient age was 51 years (range 25-82). Twelve patients were women and 3 were men. The majority of the fractures (14 out of 15) presented as an edema pattern on T2-weighted images, either diffuse (9 out of 15), or vertical (5 out of 15). One case did not show marrow edema, but rather a hypointense line. Nine patients (60%) demonstrated calcaneonavicular coalition and anterior calcaneal process fracture. In 6 patients (50%) the anterior talofibular ligament (ATFL) was thickened. Three patients did not have axial images, and were classified as non-conclusive for the ATFL evaluation. The bifurcate ligament was thickened with hyperintense signal demonstrating a sprain in 9 out of 13 (69%). Only 2 patients (16.5%) had an anterior calcaneal process fracture without any associated abnormality.

CONCLUSIONS

We believe that there is a probable association of anterior process fractures and calcaneonavicular coalitions. We also feel, based on our results and the prior literature that there is likely also an association with both ATFL injuries and bifurcate ligament injuries.

Incidence and morphologic characteristics of benign calcaneal cystic lesions on MRI

BACKGROUND

Since we have frequently noted osseous cyst-like lesions within the calcaneus on MRI studies, we sought to systematically evaluate this finding to determine the incidence and morphologic characteristics on MRI.

METHODS

Three observers blinded to age evaluated 198 MRIs of the ankle (74 males, 124 females; mean age 47 years, range 13 to 99 years), recording the presence and size of calcaneal cyst-like foci. Statistical analysis was performed to determine if there was an association with age. Additionally, MRI of 12 ankles precontrast and postcontrast were reviewed for the presence of blood vessels in the calcaneus corresponding to the location of the cyst-like lesions and 24 ankle MR arthrograms were reviewed to evaluate communication of the cyst with the adjacent joint.

RESULTS

Of the 198 ankle MRI examinations, 81 (40%) had hyperintense foci, all within the mid-calcaneal body. The size ranged from 0.01 cm(2) to 2.47 cm(2), with a mean size of 0.36 cm(2) (+/- 0.45 cm(2)). Thirty-seven (46%) were linear or elongated, whereas 44 (54%) were ovoid or round. Seven of the 81 foci (8.6% or 3.5% of the total population) were 1 cm(2) or larger. There was no significant association of patient age and presence (p = 0.49) or size (p = 0.48) of the focus. Location of the cyst-like foci, which often are ovoid or linear, corresponds to penetrating microvessels on precontrast and postcontrast MRI. One MR arthrogram showed communication of a cyst-like focus and the subtalar joint.

CONCLUSIONS

Calcaneal lesions are relatively common incidental findings on MRI. These lesions appear to represent intraosseous ganglion cysts that arise from the anterior margin of the posterior facet of the subtalar joint in the anatomical neighborhood where vessels penetrate the superior calcaneal cortex. The lesions can vary is size; however, there is no correlation between patient age and lesion size and no significant association between age and presence of these foci.

Myxoid chondrosarcoma in the calcaneus: a case report with MR imaging findings

Skeletal myxoid chondrosarcoma is an extraordinarily rare neoplasm with a distinct histological morphology. Herein, we report a case of a myxoid chondrosarcoma in the calcaneus of a 20-year-old man with a description of its MR imaging (MRI) and histological findings.

The Reverse Sural Artery Adipofasciomuscular Flap for the Reconstruction of a Heel Sinus With Underlying Calcaneal Osteomyelitis

The reverse sural artery fasciomusculocutaneous flap has become an acceptable technique of lower-limb reconstruction despite the grafted appearance of the donor site in the upper leg. In an attempt to reduce the donor-site morbidity, we describe the use of the adipofasciomuscular reverse sural artery flap in a patient with a heel sinus and underlying calcaneal osteomyelitis.

Heel spur radiotherapy and radiation carcinogenesis risk estimation

PURPOSE

Radiotherapy is a nonsurgical alternative therapy of painful heel spur patients. Nonetheless, cancer induction is the most important somatic effect of ionizing radiation. This study was designed to evaluate the carcinogenesis risk factor in benign painful heel spur patients treated by radiotherapy.

MATERIALS AND METHODS

Between 1974 and 1999, a total of 20 patients received mean 8.16 Gy total irradiation dose in two fractions. Thermoluminescent dosimeters (TLD(100)) were placed on multiple phantom sites in vivo within the irradiated volume to verify irradiation accuracy and carcinogenesis risk factor calculation. The 20 still-alive patients, who had a minimum 5-year and maximum 29-year follow-up (mean 11.9 years), have been evaluated by carcinogenic radiation risk factor on the basis of tissue weighting factors as defined by the International Commission on Radiological Protection Publication 60.

RESULTS

Reasonable pain relief has been obtained in all 20 patients. The calculated mean carcinogenesis risk factor is 1.3% for radiation portals in the whole group, and no secondary cancer has been clinically observed.

CONCLUSION

Radiotherapy is an effective treatment modality for relieving pain in calcaneal spur patients. The estimated secondary cancer risk factor for irradiation of this benign lesion is not as high as was feared.

Calcaneal osteochondroma

Osteochondromas are essentially the most common primary bone tumors. These benign cartilage producing neoplasms are generally asymptomatic and have a relatively small potential for adverse effects. HME, the familial form of this tumor, is associated with a greater incidence of complications, the most significant of which is sarcomatous degeneration to secondary chondrosarcomas. Various imaging techniques can be used to characterize these lesions, but in the absence of symptoms or signs of complications, plain-film radiography is usually sufficient for diagnosis as this tumor has a characteristic radiographic appearance. Once this benign tumor is identified and more serious forms of tumor are ruled out, treatment is generally not needed. If a malignancy is suspected, however, complete surgical excision is the preferred treatment as this usually ensures long term survival.

Correction of neglected idiopathic club foot by the Ponseti method

The Ponseti method of treating club foot has been shown to be effective in children up to two years of age. However, it is not known whether it is successful in older children. We retrospectively reviewed 17 children (24 feet) with congenital idiopathic club foot who presented after walking age and had undergone no previous treatment. All were treated by the method described by Ponseti, with minor modifications. The mean age at presentation was 3.9 years (1.2 to 9.0) and the mean follow-up was for 3.1 years (2.1 to 5.6). The mean time of immobilisation in a cast was 3.9 months (1.5 to 6.0).

A painless plantigrade foot was obtained in 16 feet without the need for extensive soft-tissue release and/or bony procedures. Four patients (7 feet) had recurrent equinus which required a second tenotomy. Failure was observed in five patients (8 feet) who required a posterior release for full correction of the equinus deformity.

We conclude that the Ponseti method is a safe, effective and low-cost treatment for neglected idiopathic club foot presenting after walking age.

Anatomic variants associated with peroneal tendon disorders: MR imaging findings in volunteers with asymptomatic ankles

PURPOSE

To evaluate prospectively, on magnetic resonance (MR) images in volunteers with asymptomatic ankles, various features of anatomic variants that are potentially associated with peroneal tendon disorders.

MATERIALS AND METHODS

The study had institutional review board approval; informed consent was obtained from each volunteer. The prevalence of accessory peroneus quartus muscles, the location of the muscle-tendon junction of the peroneus brevis muscle, the prevalence and size of the peroneal tubercle and the retrotrochlear eminence, and the shape of the retromalleolar fibular groove were evaluated on MR images in 65 volunteers with asymptomatic ankles (35 women, 30 men; age range, 23-70 years; median age, 45 years). MR images were analyzed by two radiologists in consensus. The relationship between anatomic features and age and sex was analyzed by using Spearman rank correlation and the Wilcoxon rank sum test.

RESULTS

A peroneus quartus muscle was identified in 11 (17%) ankles. Ninety percent of the musculotendinous junctions of the peroneus brevis muscle were located in a range between 27 mm proximal to and 13 mm distal to the fibular tip (median, 0 mm). A peroneal tubercle was identified in 36 (55%) ankles. Ninety percent of all peroneal tubercles were 4.6 mm or smaller (median height, 2.9 mm). A retrotrochlear eminence was seen in all ankles (median, 3.0 mm; 90% were 4.6 mm or smaller). The retromalleolar groove was concave in 18 (28%), flat in 28 (43%), convex in 12 (18%), and irregular in seven (11%) volunteers. A significant difference (P = .04) for the height of the retrotrochlear eminence was found between men (median, 3.4 mm) and women (median, 2.5 mm). All other P values were greater than .05.

CONCLUSION

Anatomic variants thought to predispose individuals to peroneal tendon disorders can be seen in volunteers with asymptomatic ankles.

Biomechanical evaluation of primary stiffness of tibiotalocalcaneal fusion with intramedullary nails

BACKGROUND

Intramedullary implants are being used with increasing frequency for tibiotalocalcaneal fusion (TTCF). Clinically, the question arises whether intramedullary (IM) nails should have a compression mode to enhance biomechanical stiffness and fusion-site compression. This biomechanical study compared the primary stability of TTCF constructs using compressed and uncompressed retrograde IM nails and a screw technique in a bone model.

METHODS

For each technique, three composite bone models were used. The implants were a Biomet nail (static locking mode and compressed mode), a T2 femoral nail (compressed mode); a prototype IM nail 1 (PT1, compressed mode), a prototype IM nail 2 (PT2, dynamic locking mode and compressed mode), and a three-screw construct. The compressed contact surface of each construct was measured with pressure-sensitive film and expressed as percent of the available fusion-site area. Stiffness was tested in dorsiflexion and plantarflexion (D/P), varus and valgus (V/V), and internal rotation and external rotation (I/E) (20 load cycles per loading mode).

RESULTS

Mean contact surfaces were 84.0 +/- 6.0% for the Biomet nail, 84.0 +/- 13.0% for the T2 nail, 70.0 +/- 7.2% for the PTI nail, and 83.5 +/- 5.5% for the compressed PT2 nail. The greatest primary stiffness in D/P was obtained with the compressed PT2, followed by the compressed Biomet nail. The dynamically locked PT2 produced the least primary stiffness. In V/V, PT1 had the (significantly) greatest primary stiffness, followed by the compressed PT2. The statically locked Biomet nail and the dynamically locked PT2 had the least primary stiffness in V/V. In I/E, the compressed PT2 had the greatest primary stiffness, followed by the PT1 and the T2 nails, which did not differ significantly from each other. The dynamically locked PT2 produced the least primary stiffness. The screw construct's contact surface and stiffness were intermediate.

CONCLUSIONS

The IM nails with compression used for TTCF produced good contact surfaces and primary stiffness. They were significantly superior in these respects to the uncompressed nails and the screw construct. The large contact surfaces and great primary stiffness provided by the IM nails in a bone model may translate into improved union rates in patients who have TTCF.

Modified Essex-Lopresti / Westheus reduction for displaced intra-articular fractures of the calcaneus. Description of surgical technique and early outcomes

We describe a modification of the classical Essex-Lopresti manoeuvre for the indirect reduction and stabilisation of displaced intra-articular fractures of the calcaneus. The radiological and functional results achieved using this technique in 15 patients is presented. Ten tongue-shaped and 8 joint depression type fractures were treated by the new method, incorporating the use of an additional traction pin. The pre and postoperative Böhler angles as well as the correction achieved were documented. Functional assessment was carried out using the Maryland Foot Score. The mean pre-operative Böhler angle in the joint depression group was 5.5 degrees, and in the tongue shaped fracture group 5 degrees. The mean postoperative Böhler angle in the joint depression group was 15.8 degrees, and in the tongue shape group was 23.25 degrees. At a mean follow-up of 28 months the joint depression group scored 51/100 on the foot score, and the tongue shaped fracture group 77/100. The mean correction achieved as well as the mean overall functional scores were significantly better in the tongue shaped group. The technique described has much promise in the management of selected displaced intra-articular fractures of the calcaneus (true tongue shaped / Sanders II), and may also have a limited role in other fracture types in patients with significant co-morbidities, soft tissue compromise and poor healing potential.

Angle analysis of Haglund syndrome and its relationship with osseous variations and Achilles tendon calcification

BACKGROUND

Haglund syndrome is a cause of posterior heel pain. The prominent posterosuperior projection into the retrocalcaneal bursa is thought to be a major etiology. Many methods have been proposed to measure the posterosuperior projection of the tuberosity into this bursa. The Fowler angle and the parallel pitch lines are the most frequently used. However, the relation between symptomatic Haglund syndrome and the measuring methods, especially the Fowler angle and parallel pitch lines, is not clear. The purposes of this paper were to study the predictive value of the most frequently used measurement methods to evaluate bursal impingement and to determine if other osseous variations and Achilles tendon calcification are associated with the development of Haglund syndrome.

METHODS

From October, 1996, to March, 2003, we evaluated 37 heels in 31 patients with symptomatic Haglund syndrome, and 40 heels in 27 individuals without posterior heel pain. On a lateral view radiograph, the Fowler angle, and the parallel pitch lines were measured, in addition to Achilles tendon calcification and the osseous variations, such as a posterior calcaneal step spur or plantar osseous projection.

RESULTS

The average Fowler angles in the control group and study group were 62.31 +/- 7.79 degrees and 60.14 +/- 7.01 degrees, respectively. There was no statistically significant difference (p = 0.490). The positive parallel pitch lines in the symptomatic group were 56.8% and in the control group 42.5%. There was no statistically significant difference (p = 0.474) between the groups.

CONCLUSIONS

No statistically significant differences were noted between the groups concerning the Fowler angle and parallel pitch lines. The posterior calcaneal step spur and Achilles tendon calcification were statistically significant between these two groups. The Fowler angle and parallel pitch lines were of little predictive value for the Haglund syndrome.

Tranilast Suppresses the Disease Development of the Adjuvant- and Streptococcal Cell Wall-Induced Arthritis in Rats

This study explores the effects of the anti-allergic and anti-fibrotic agent tranilast on adjuvant- and streptococcal cell wall-induced arthritis in rats, animal models of rheumatoid arthritis in humans. Tranilast (150 or 300 mg/kg, twice daily) or vehicle only was administered orally to the two arthritis models, from 17 days before sensitization. As a comparative control, methotrexate (0.1 mg/kg, once daily) was given to another group. Tranilast suppressed the increase in foot volumes, paw thicknesses, clinical scores, and histopathological scores of the ankle joints in both models dose-dependently. In addition, the fibrosis indices of the ankles were dramatically decreased by tranilast in both of the models. Compared to the effects of methotrexate, tranilast seemed to work more effectively in the streptococcal cell wall-induced arthritis model than in the adjuvant-induced arthritis model. From these observations, it can be concluded that tranilast suppresses the development of arthritis in multiple models and is potentially a novel therapeutic agent for human rheumatoid arthritis.

Association between an AluI polymorphism in the calcitonin receptor gene and quantitative ultrasound parameters in Korean men

OBJECTIVE

The purpose of this study was to investigate the association between an AluI RFLP of the calcitonin receptor (CTR) gene and quantitative ultrasound (QUS) parameters in Korean men, and the interaction with nutrition as a lifestyle factor.

MATERIALS AND METHODS

Broadband ultrasound attenuation, speed of sound and stiffness index of the calcaneus were measured using an ultrasound bone densitometer in 201 Korean men (mean age +/- SD: 51.6 +/- 11.7 years). The PCR-RFLP method was used to analyze an AluI polymorphism in the CTR gene.

RESULTS

In all subjects, the distribution of CC, CT and TT genotypes occurred with frequencies of 87.1, 12.4 and 0.5%, respectively. When stratified by omnivore and vegetarian groups, there was a significant association between an AluI polymorphism in the CTR gene and QUS parameters such as speed of sound and stiffness index in only vegetarian subjects.

CONCLUSION

Our data suggest that the AluI polymorphism of the CTR gene can be useful as a genetic marker in the interindividual susceptibility of QUS parameters by the interaction with nutritional status as a lifestyle factor.

Incidence and MR imaging features of fractures of the anterior process of calcaneus in a consecutive patient population with ankle and foot symptoms

OBJECTIVE

To determine the incidence, appearances and associated injuries of fractures affecting the anterior process of calcaneus from a general population with foot and ankle symptoms.

DESIGN AND PATIENTS

A retrospective review of foot and ankle MR imaging procedures was performed for detection of cases with a fracture affecting the anterior process of calcaneus over a four year period. Radiographs, MR imaging studies, radiology reports, medical records, and operative notes were reviewed. Imaging analysis included fracture pattern, displacement, associated fractures, and presence of tendon and ligamentous injuries.

RESULTS

The incidence of anterior process of calcaneus fracture on MR imaging was 0.5% (14/2577). Fractures were more common in female subjects (71%, 10/14). Fracture orientation was predominantly vertical (93%, 13/14). No comminuted fractures were seen and only three fractures were displaced. Three of the eight MR imaging evident fractures of anterior process of calcaneus were seen on radiographs. Associated fractures of the talus (n=5), navicular bone (n=3), cuboid (n=2), and calcaneal body (n=1) were noted. Associated injuries to the anterior talofibular ligament (n=3) and tears of the peroneus brevis (n=3) and peroneus longus (n=1) tendons were present. All fractures were treated non-operatively. Two patients had subtalar joint steroid injection for symptomatic relief.

CONCLUSIONS

Fractures of the anterior process of the calcaneus are uncommon in MR examinations of a general population of patients with foot and ankle symptoms. Although anterior process of calcaneus fractures are rare, there was a moderately high incidence of associated bone and soft-tissue injuries.

Treatment of a solitary calcaneal cyst with endoscopic curettage and percutaneous injection of calcium phosphate cement

We report the case of a 35-year-old man who presented with pain in the right heel. Plain radiographs and computerized tomography revealed a solitary cyst of the calcaneus. Endoscopic curettage of the lesion and endoscopically assisted filling of the lesion with calcium phosphate bone cement injected percutaneously were performed. After 12 months, no recurrence was noted and the patient was symptom free.

Marrow changes in anorexia nervosa masking the presence of stress fractures on MR imaging

Patients with anorexia nervosa (AN) usually have abnormal bone and bone marrow metabolism resulting in osteopenia and serous bone marrow change. There is an increased risk of stress/insufficiency fractures and these can be the first presentation of AN. This case report describes a patient with previously undiagnosed AN who presented with foot pain. The serous bone marrow changes of AN were found to mask the MR imaging features of stress fractures, as both had low T1w and high T2w and STIR signal intensities. Contrast enhancement was not helpful but actually masked fractures. Scintigraphy was helpful. The radiologist might be the first clinician to raise the possibility of AN and should be aware of the difficulties in diagnosing stress fractures in bones with underlying serous bone marrow change. In this severe case of AN even the heel fat pad and the fat pad in Kager's triangle had undergone serous change.

[The calcaneus as the site of manifestation for osteoporosis-associated fractures: age- and sex-specific changes in calcaneal morphology correlate with the incidence and severity of intra-articular calcaneal fractures]

BACKGROUND

While it is recognized that trauma energy at the time of injury is an important factor in the pathogenesis and severity of calcaneal fractures, the possible role of changes in calcaneal microarchitecture remains largely undefined. The purpose of this study was to determine whether the calcaneal bone structure changes with age and to address if local bone mass is of clinical relevance in respect to the occurrence and complexity of calcaneal fractures.

MATERIAL AND METHODS

The radiographic and clinical data of 182 patients with intra-articular calcaneal fractures were analyzed to provide correlative clinical evidence for a relation between local bone mass and fractures of the calcaneus. To measure bone mass, 60 calcanei were harvested from 30 age- and gender-matched patients at autopsy.

RESULTS

The average age at the time of fracture was higher in females (46.0+/-18.3 years) than in males (39.9+/-13.9 years). Furthermore, the relative frequency of fractures during aging shifted from males to females and the frequency of compound fractures was higher in females (65%) than in males (48%). The calcaneal bone mass was significantly reduced by 19% in older females (female symbol 20-40 years: 292 mg/cm(3); female symbol 61-80 years: 237 mg/cm(3); p<0.05).

CONCLUSION

The calcaneus displayed age- and gender-related changes in its microarchitecture that are known to reduce the biomechanical stability of trabecular bone. These results suggest that bone mass and structure are risk factors in respect to the occurrence and severity of calcaneal fractures.

Boehler's angle and the critical angle of Gissane are of limited use in diagnosing calcaneus fractures in the ED

STUDY OBJECTIVES

The aim of this study was to determine the use of Boehler's angle (BA) and the critical angle of Gissane (CAG) in diagnosing calcaneus fractures in the ED.

DESIGN

The study was conducted as a randomized, blinded, case-control trial.

CASES

One hundred thirty-three patients older than 15 years were included in the study. Sixty-five patients with computed tomography-verified calcaneus fractures (gold standard) and 68 ED patients with lateral foot or ankle x-rays without calcaneus fractures were included in the study.

METHODS

One second-year emergency medicine resident, 1 third-year emergency medicine resident, 2 board-certified emergency medicine attending physicians, and 1 board-certified radiologist prospectively reviewed all films using the Picture Archival and Communication System digital radiology system. Cases and controls were randomized and the participants were blinded to final radiographic diagnoses. Participants determined whether there was a fracture on each x-ray and measured BA and the CAG using the digital angle tool in the Picture Archival and Communication System.

RESULTS

Emergency physicians were 97.9% accurate in diagnosing calcaneus fractures (range, 97% to 99%). The mean kappa value for emergency physicians was 0.96 (range, 0.94-0.985). Receiver operating characteristic curves were constructed for BA and the CAG. When compared with the gold standard, the area under the curve for BA ranged from 0.82 to 0.88. The area under the curve for the CAG ranged from 0.45 to 0.67. BA had an interclass correlation coefficient of 0.84 (95% confidence interval, 0.79-0.87). The CAG interclass correlation was 0.52 (95% confidence interval, 0.43-0.60). One fracture was missed by the radiologist and all of the emergency physicians because it was only visible on computed tomography.

CONCLUSION

BA is somewhat helpful and the CAG is not useful in diagnosing calcaneus fractures in the ED. Interrater reliability for BA is excellent, but for the CAG, it is poor. Emergency physicians were 97.9% accurate in making the diagnosis by reviewing the plain films without "assistance" of the angle measurements.

First histological observations on the incorporation of a novel nanocrystalline hydroxyapatite paste OSTIM in human cancellous bone

Background:

A commercially available nanocrystalline hydroxyapatite paste Ostim^® has been reported in few recent studies to surpass other synthetic bone substitutes with respect to the observed clinical results. However, the integration of this implantable material has been histologically evaluated only in animal experimental models up to now. This study aimed to evaluate the tissue incorporation of Ostim^® in human cancellous bone after reconstructive bone surgery for trauma.

Methods:

Biopsy specimens from 6 adult patients with a total of 7 tibial, calcaneal or distal radial fractures were obtained at the time of osteosynthesis removal. The median interval from initial operation to tissue sampling was 13 (range 3–15) months. Samples were stained with Masson-Goldner, von Kossa, and toluidine blue. Osteoid volume, trabecular width and bone volume, and cortical porosity were analyzed. Samples were immunolabeled with antibodies against CD68, CD56 and human prolyl 4-hydroxylase to detect macrophages, osteoblasts, and fibroblasts, respectively. TRAP stainings were used to identify osteoclasts.

Results:

Histomorphometric data indicated good regeneration with normal bone turnover: mean osteoid volume was 1.93% of the trabecular bone mass, trabecular bone volume – 28.4%, trabecular width – 225.12 μm, and porosity index – 2.6%. Cortical and spongious bone tissue were well structured. Neither inflammatory reaction, nor osteofibrosis or osteonecrosis were observed. The implanted material was widely absorbed.

Conclusion:

The studied nanocrystalline hydroxyapatite paste showed good tissue incorporation. It is highly biocompatible and appears to be a suitable bone substitute for juxtaarticular comminuted fractures in combination with a stable screw-plate osteosynthesis.

Use of an Arterial Tourniquet to Achieve Complete Radiofrequency Ablation of a Renal Metastasis

Radiofrequency (RF) coagulation of skeletal metastases is usually performed for pain relief. However, patients with solitary skeletal metastasis may benefit from more aggressive attempts to achieve local control. The authors report a case in which an arterial tourniquet was used to enhance the effectiveness of RF treatment of a calcaneal renal cell metastasis, leading to long-lasting local control with preservation of ambulation.

Insufficiency fractures of the calcaneus: a diagnostic pitfall for ankle arthritis

OBJECTIVE

To highlight the differential diagnosis between insufficiency fractures (IF) of the calcaneus and arthritis of the ankle.

METHODS

We retrospectively reviewed clinical charts and imaging findings for 6 patients with 7 IF of the calcaneus who were referred with the diagnosis of ankle arthritis. The main predisposing factors, clinical features, therapy, and outcome were recorded. IF was considered when occurring spontaneously or with minimal trauma.

RESULTS

All patients were women, with a mean age of 73.8 +/- 6.3 years. The median delay to diagnosis was 6 weeks (25th, 75th percentiles: 1, 12). Two had previous IF at other locations. Three patients had a history of chronic inflammatory conditions while receiving longterm steroid therapy. All complained of moderate to severe pain that interfered with daily activities and was relieved with rest. Physical examination revealed ankle inflammation in all cases. Radiographs were normal in 5 patients. Magnetic resonance imaging (MRI) was diagnostic. All received conservative treatment with complete resolution of symptoms without sequelae.

CONCLUSION

IF of the calcaneus are relatively rare but can be mistaken for ankle arthritis. MRI is recommended because this type of fracture is difficult to detect on plain films. Although IF have a good prognosis with conservative treatment, increased awareness is of importance for prompt diagnosis and proper management.

Characterization of trabecular bone structure from high-resolution magnetic resonance images using fuzzy logic

The purpose of this work was to apply fuzzy logic image processing techniques to characterize the trabecular bone structure with high-resolution magnetic resonance images. Fifteen ex vivo high-resolution magnetic resonance images of specimens of human radii at 1.5 T and 12 in vivo high-resolution magnetic resonance images of the calcanei of peri- and postmenopausal women at 3 T were obtained. Soft segmentation using fuzzy clustering was applied to MR data to obtain fuzzy bone volume fraction maps, which were then analyzed with three-dimensional (3D) fuzzy geometrical parameters and measures of fuzziness. Geometrical parameters included fuzzy perimeter and fuzzy compactness, while measures of fuzziness included linear index of fuzziness, quadratic index of fuzziness, logarithmic fuzzy entropy, and exponential fuzzy entropy. Fuzzy parameters were validated at 1.5 T with 3D structural parameters computed from microcomputed tomography images, which allow the observation of true trabecular bone structure and with apparent MR structural indexes at 1.5 T and 3 T. The validation was statistically performed with the Pearson correlation coefficient as well as with the Bland-Altman method. Bone volume fraction correlation values (r) were up to .99 (P<.001) with good agreements based on Bland-Altman analysis showing that fuzzy clustering is a valid technique to quantify this parameter. Measures of fuzziness also showed consistent correlations to trabecular number parameters (r>.85; P<.001) and good agreements based on Bland-Altman analysis, suggesting that the level of fuzziness in high-resolution magnetic resonance images could be related to the trabecular bone structure.

Metrical and non-metrical assessment of population affinity from the calcaneus

To date, there are no metric standards for differentiating between population groups from measurements of the calcaneus in South Africa. Previously, some of the measurements of the calcaneus have been used for sex determination in Americans, Europeans, Italians and South Africans. However, the variations in the number of articular facet present on the superior surface of the calcaneus have been observed in different population groups. This study aims at investigating the potentials of measurements of the calcaneus in diagnosing population affinity and observes population variations of the number of articular facet present on its superior surface in indigenous South Africans and those of European descent. Nine measurements were taken from 180 non-pathological left calcanei in a sample of known sex and population affinity obtained from the Raymond A. Dart Collection of Human Skeletons. Three articular facet types were observed. A significantly higher incidence of type A was observed in South Africans of European descent (SAED) population group while type B predominated in the indigenous South African (ISA) population group. Type C even though rare was found only in ISA group. The metrical data were subjected to discriminant function analyses. The average accuracy in correct classification (81-89%) obtained for the discriminant function equations derived in this study may assist in the determination of population affinity when the calcaneus is present for analysis in forensic cases.

Bone microarchitecture of the calcaneus and its changes in aging: a histomorphometric analysis of 60 human specimens

Bone structure and quality are an important parameter in the propensity of bone to fracture. Although the calcaneus is used as diagnostic reference site for osteoporosis by ultrasound, its structure has never been analyzed in detail. The purpose of this study was therefore to histomorphometrically analyze the trabecular microarchitecture of the calcaneus, and to determine whether the calcaneal bone structure is changing with age. Sixty complete human calcanei were harvested from thirty age- and gender-matched patients at autopsy. Each of the three different age groups (group I: 20 to 40, group II: 41 to 60, group III: 61 to 80 years of age) was represented by 20 specimens. The specimens were subjected to radiographic, microCT, and histologic analysis. Bone structure and bone mass of the calcaneus were quantified for three different regions of interest: the anterior ROI, the superior ROI (the subtalar region under the posterior facet), and the posterior ROI. An iliac crest biopsy was obtained from all patients to exclude any metabolic bone disease. Histomorphometric analysis revealed significant differences in bone volume within the calcaneus with highest values in the superior ROI: age group I: 31.3% (27.8-34.8%); II: 25.5% (22.1-28.9%); III: 18.9% (16.6-21.2%) and lowest bone volumes in the anterior ROI; age group I: 6.2% (4.8-7.6%); II: 3.6% (2.1-5.1%); III: 3.9% (2.9-4.9%). There was a significant age-related decrease in bone volume (BV/TV) in aging. Interestingly, this bone loss was most prominent in the superior ROI, with a 39% decrease in BV/TV between age group I and III (p < 0.001). Qualitative and structural analysis of trabecular number, thickness, and spacing demonstrated that the bone loss in the thalamic portion of the calcaneus was due to the transition of plate-like trabecular elements into a rod-like structure. In conclusion, our study demonstrated that the calcaneus displayed age-related changes in its microarchitecture that are known to reduce the biomechanical stability of trabecular bone, and that the age-related bone loss was most prominent in the region adjacent to the posterior facet (superior ROI). These results suggest that bone mass and structure are risk factors in respect to the occurrence and severity of calcaneal fractures, and indicate that calcaneal fractures are at least in part osteoporotic fractures.

Percutaneous intramedullary decompression, curettage, and grafting with medical-grade calcium sulfate pellets for unicameral bone cysts in children: a new minimally invasive technique

Several treatment options exist for unicameral bone cysts (UBCs), including observation, steroid injection, bone marrow injection, and curettage and bone grafting. These are all associated with high recurrence rates, persistence, and occasional complications. Newer techniques have been described, most with variable success and only short follow-up reported. Because of these factors, a new minimally invasive percutaneous technique was developed for the treatment of UBCs in children. Twenty-eight children with UBCs who underwent percutaneous intramedullary decompression, curettage, and grafting with medical-grade calcium sulfate (MGCS) pellets by the senior author (J.P.D.) between April 2000 and April 2003 were analyzed as part of a pediatric musculoskeletal tumor registry at a large tertiary children's hospital. Four patients were lost to follow-up, and the remaining 24 patients had an average follow-up of 21.9 months (range 4-48 months). Twelve patients were followed for at least 24 months. Six of the 24 children had received previous treatment of their UBC, most often at an outside institution. Follow-up was performed through clinical evaluation and radiographic review. Postoperative radiographs at most recent follow-up showed complete healing, defined as more than 95% opacification, in 22 of 24 patients (91.7%). One patient (4.2%) demonstrated partial healing, defined as 80% to 95% opacification. One patient had less than 80% radiographic healing (4.2%). All 24 patients returned to full activities and were asymptomatic at most recent follow-up. The only complication noted was a superficial suture abscess that occurred in one patient; this resolved with local treatment measures. The new minimally invasive technique of percutaneous intramedullary decompression, curettage, and grafting with MGCS pellets demonstrates favorable results with low complication and recurrence rates compared with conventional techniques. The role of intramedullary decompression as a part of this percutaneous technique is discussed.

Prominent Vascular Remnants in the Calcaneus Simulating a Lesion on MRI of the Ankle: Findings in 67 Patients with Cadaveric Correlation

OBJECTIVE

Our objective was to prove through cadaveric correlation that a frequently seen focus of MRI signal in the calcaneus is benign.

CONCLUSION

A characteristic focus of signal (increased T2, decreased T1) in the calcaneus near the attachment of the cervical and interosseous ligaments is a common, benign finding frequently seen on MRI of the foot and ankle.

Osseous lesion of the calcaneus following the use of shock wave therapy in a horse

An 8-year-old Dutch warmblood gelding was presented with a mechanical lameness (2/10) because of the presence of a soft tissue injury on the top of the right tuber calcanei. Plain radiographs of the tarsus demonstrated the presence of soft tissue swelling caudal to the right tuber calcanei, without osseous involvement, and ultrasonography revealed excessive scar tissue within and around the superficial digital flexor tendon. Extra-corporeal shock wave therapy was applied on the right hock to decrease the amount of scar tissue. One month after the therapy the lameness was greater (3/10) and a marginal increase in the size of the swelling was found. Periosteal new bone formation associated with an ill-defined radiolucent area and two bony fragments were detected radiographically at the caudo-proximal aspect of the right tuber calcanei. A blister containing oil of croton, camphor, pine and thyme, turpentine and cantharides was applied on the right calcaneus. Twenty days after blister application, the size of the swelling had been reduced by 50% and the degree of lameness had also been decreased (1/10). On clinical re-evaluation 6 months after treatment, the degree of lameness was stable (1/10) and flexion test of the limb was negative.

Osteoid osteoma of the calcaneus: percutaneous radiofrequency ablation

Osteoid osteoma of the foot can pose particular problems in diagnosis, especially when positioned in a juxta-articular location. It can cause reactive synovitis and simulate arthritis without periostitis. An atypical presentation may delay diagnosis and thus delay treatment. Different modes of treatment have been described including medical management with nonsteroidal, antiinflammatory drugs, and open surgical resection with intralesional, marginal, or wide surgical margins. In recent years, several computed tomography-guided percutaneous techniques have been used to achieve ablation of the nidus with minimal tissue invasion. We report a case of a 39-year-old man with an 8-month history of persistent foot pain who underwent percutaneous radiofrequency ablation of an osteoid osteoma involving the calcaneus. The patient related an immediate relief of pain and had no recurrence of symptoms or the lesion at 3-year follow-up.

The peroneal tubercle: description, classification, and relevance to peroneus longus tendon pathology

BACKGROUND

The size and configuration of the peroneal tubercle has been implicated in the pathogenesis of peroneal tendon tears and tenosynovitis. The purpose of this study was to determine the size and prevalence of the peroneal tubercle and devise a classification scheme according to the structure of the tubercle.

METHODS

One hundred and seventeen calcanei were selected from 59 human skeletons in an osteological collection (one calcaneus was missing). Three were excluded because of the poor condition, leaving 114 calcanei. The peroneal tubercle was measured in length, height, and depth and its structure subjectively described as flat, prominent, concave, or tunnel for each specimen when present.

RESULTS

This study revealed a peroneal tubercle prevalence of 90.4% (103) in 114 calcanei. The average length, height, and depth of the tubercle were 13.04 mm (range 3.61 mm to 26.66 mm), 9.44 mm (range 3.67 mm to 23.40 mm), and 3.13 mm (range 1 to 10), respectively. The peroneal tubercle was classified structurally as flat in 44 (42.7%), prominent in 30 (29.1%), concave in 28 (27.2%), and tunnel in one (1.0%).

CONCLUSION

This data may further help to understand the size and assorted configurations of the peroneal tubercle and how they relate to peroneus longus tendon pathology.

Ultrasound detection of entheseal insertions in the foot of patients with spondyloarthropathy

The aim of the study was to evaluate entheseal involvement in the foot of patients with spondyloarthropathy (SpA) by ultrasonographic (US) examination and compare the results with clinical and radiological findings. Forty-four patients (27 men, 17 women) with a diagnosis of SpA were recruited. Patient evaluation included physical examination (swelling and pain), Bath Ankylosing Spondylitis Radiological Index, Bath Ankylosing Spondylitis Disease Activity, Bath Ankylosing Spondylitis Metrological Index, and laboratory parameters (erythrocyte sedimentation rate, C-reactive protein). Foot x-rays of the patients were assessed and scored according to SpA Tarsal Radiographic Index (SpA-TRI). A high-resolution US was used to examine the tendon and ligament insertion sites in the foot, and the findings were scored according to Glasgow Ultrasound Enthesitis Scoring System (GUESS). The mean age and disease duration of the patients were 39.9+/-12.5 and 9+/-8.2 years, respectively. US revealed pathological findings in 25 of 44 (56.8%) patients, most of whom exhibited no clinical signs of foot involvement. Pain and swelling at entheseal insertions were detected in only 16 (37%) patients. The mean GUESS score and SpA-TRI score were 2.2+/-2.5 and 3.3+/-3.7, respectively. There was a correlation between the scores of GUESS and SpA-TRI, particularly at the Achilles and plantar fascia insertion sites. The mean score of SpA-TRI was higher in patients with enthesopathy, detected by US, than in patients without enthesopathy (4.6+/-4.4 vs 1.8+/-2.1). There was no significant correlation between the mean GUESS score and clinical and laboratory variables. In conclusion, involvement of tendon and entheses is not rare, and US is a valuable diagnostic method in detecting subclinical enthesopathic changes. The GUESS and SpA-TRI are suggested in quantifying US and radiological changes in the foot of patients with SpA.